The 'slot' is the area between the last offensive lineman on either side of the line of scrimmage and the wide receiver on that side. A player who lines up between those two players and behind the line of scrimmage is a slotback.

Duties of the slotback

There are a number of different jobs a slotback may take up on the field. Primarily, they are used as hybrid running backs/receivers. However they are often used to block any player on the defensive team who breaks through the line of scrimmage, thus as a precaution to prevent the sacking of the quarterback. They are preferred over the wide receiver or tight end for receiving short passes or handoffs due to their positioning being closer to the quarterback. When formations containing slotbacks are used in American football the team often has to go without a tight end, a fullback or a running back due to there being only 11 men on the offense and 7 being on the offensive line, one reason they are rarer in the American game.

Slotbacks are used effectively in flexbone formations, in which they are used as extra receivers.